Product selection support
Discuss water conditions, process position and current products.
Source photograph; appearance, grade and supplied packaging follow the agreed product documents.
Source image: No machine-readable author provided. Walkerma assumed (based on copyright claims).; ENVO presentation layout · ENVO outer layout / Public domain · Source
Reduction, dechlorination & oxygen scavenging
Sodium Metabisulfite
SMBS / SMB
A reducing and dechlorinating raw material for suitable membrane protection and other specified residual-oxidant control steps.
Confirmed availableBase chemicals
- Chemical identity
- Reference CAS: 7681-57-4. Confirm the exact chemical, hydration or formulation against the current product SDS.
- Product form
- White crystalline powder.
Add application & specification details
Application value
Uses and application conditions
Residual-chlorine reduction & dechlorination; Chromium speciation, reduction & separation
Use these checks to compare equivalent supply specifications and narrow the candidate range for your actual process.
Specification & document coordination
Align specification basis, test methods and grade-specific documents.
Packaging & supply coordination
Review quantity, packaging and destination requirements.
Specifications & selection
Specifications and order requirements
Discuss your current grade or operating conditions. ENVO codes identify sales requirements; manufacturer grades, supply specifications, test methods and document versions are confirmed for the selected product.
ENVO-SMBS-S96Catalogue 96 grade
Na2S2O5 ≥96.0%.
ENVO-SMBS-S98Catalogue 98 grade
Na2S2O5 ≥98.0%.
Application conditions & technical scope
Specify the reduction target and monitoring basis, coordinating with membrane or downstream biological processes. Food grade does not replace drinking-water end-use documents.
Appearance and supplied form
Confirm the form before comparing specifications.
Check the required form, then compare the composition, specifications and test conditions of the specific grade.
Product forms to compare
Fine crystalline powder
White to slightly yellow
Appearance information supports initial screening only. Color cannot establish chemical identity, concentration or quality grade. Confirm the actual batch using supply documents and samples.
Appearance and technical references
These public sources help check product categories, possible appearances and general application limits. They do not replace the TDS, SDS or batch COA for a specific ENVO grade.
- BASF · Sodium metabisulfite product range
White fine crystalline powder; industrial grade may be slightly yellow
- BASF · Sodium metabisulfite SDS
Reducing-feedstock identity and compatibility
- ENVO Chemical · Sodium Metabisulfite ENVO original catalogue
Associates the product page with a historical photograph; does not establish the current batch or the rights chain
- Esseco USA · Sodium Metabisulfite Technical Grade product specification
Independent manufacturer information for white to slightly yellow crystals; its specifications are not ENVO guarantees
- Walkerma / Wikimedia Commons · Sodium metabisulfite sample photograph
The original author identifies the sodium metabisulfite sample and public-domain release; technical appearance claims still rely on BASF/Esseco information
Application issues and troubleshooting
Sodium Metabisulfite — troubleshooting checks
Review symptoms, possible causes and verification steps together to prepare a more focused product-selection discussion.
01Abnormal oxidant residual before membranes after sodium metabisulfite treatment
- Possible causes
- Oxidant measurement basis, active reducing component or site mixing/monitoring may be mismatched.
- Investigation and resolution
- Specify free/total oxidant and process location; assess chemical quality separately from actual residual monitoring.
- Checks required
- Oxidant type, monitoring method, membrane model, current product and batch documents.
- Application limits
- Do not substitute products using a generic ratio or treat dechlorination feedstock as a complete membrane-protection program.
02Sodium metabisulfite assay and dosage comparisons are inconsistent
- Possible causes
- Pentahydrate/anhydrous forms or active-content measurement bases differ; storage may also affect condition.
- Investigation and resolution
- Align salt form and current testing basis, then compare under actual system monitoring.
- Checks required
- Na₂S₂O₅ content; impurities; solution preparation/storage requirements; sampling and monitoring; membrane-supplier requirements; production/arrival timing, packaging and storage information.
- Application limits
- Crystal appearance and color cannot replace assay tests; acceptance documents must match this delivery batch.
03Problems persist downstream after dechlorination
- Possible causes
- Reducing-agent residual, feedwater changes or downstream membrane/biological conditions may not have been fully considered.
- Investigation and resolution
- Track oxidant removal separately from downstream water quality and membrane/biological compatibility, clarifying process limits.
- Checks required
- Inlet/outlet water and residual records, downstream use, current monitoring and operating information.
- Application limits
- Do not independently mix with acids or incompatible oxidants; follow the corresponding SDS and system procedures.
Applications
See where this product fits.
Technical documentation
Get the information your purchasing decision needs.
Technical data sheet
Product properties, test basis and specification details.
Safety data sheet
Composition, handling, storage and transport information.
Certificate of analysis
Batch-specific analytical items and results.
Certification & use documents
Review the scope for the product and destination market.
Packaging & delivery
Confirm net weight, package material, label, delivery condition and destination documents for the selected product and order.
Technical references & scope
- NIH PubChem: Sodium Metabisulfite
- Avantor: Dechlorination Technical Note
- DuPont FilmTec: Reverse-Osmosis Membrane Technical Manual
Industry references describe general uses. Product specifications, certifications and application results require the corresponding supplier documentation.
More questions, answered.
Abnormal oxidant residual before membranes after sodium metabisulfite treatment — what should I check?
Specify free/total oxidant and process location; assess chemical quality separately from actual residual monitoring.
What should I compare when buying Sodium Metabisulfite?
Share the application, current product, purchase quantity and delivery location to help confirm a suitable specification. Key checks include: Na₂S₂O₅ content; Impurities; Solution preparation & storage requirements; Sampling & monitoring; Membrane supplier requirements. Compare the current grade document and the same test basis before choosing an alternative.
Which documents should accompany a Sodium Metabisulfite enquiry?
Request the current grade-specific TDS and product SDS, the COA for the actual supplied batch, and any intended-use documents required for the destination. Share the application, specification, quantity and delivery requirements. Document version, batch coverage and public-release scope are confirmed for the specific request.
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